Harmon was a valuable Patriots defender for seven seasons, serving as the team’s third safety behind Devin McCourty and Patrick Chung. Drafted in the third round in 2013, he missed just one game and tallied 17 regular-season interceptions — the most by any Patriots player during that span — earning the nickname “The Closer” for his knack for hauling in game-sealing picks in the fourth quarter.

The Patriots won three Super Bowls during Harmon’s tenure and played in another. His departure leaves New England lean on safety depth, with only Terrence Brooks, Malik Gant, Obi Melinfonwu and Adarius Pickett on the depth chart behind McCourty and Chung. Slot corner Jonathan Jones also can play safety, however, and Jason McCourty and Joejuan Williams have made cameos there in the past.

Harmon joins a growing roster of ex-Patriots now plying their trade in Detroit. The Lions, coached by former Patriots defensive coordinator Matt Patricia, agreed to terms with linebacker Jamie Collins and defensive tackle Danny Shelton this week and already employed defensive end Trey Flowers and wide receiver Danny Amendola.